.createbox{
    width: 100%;
    height: 100%;
}

.addcontex{
    width: 500px;
    height: 500px;
    margin: 0 auto;
    padding-top: 30px;
    padding-left: 60px;
}

.btns{
    margin-top: 20px;
    width: 100px;
    height: 40px;
    background: red;
    text-align: center;
    line-height: 40px;
    color: #fff;
}